Martha, level 9 half-elven Totemic Druid, adventuring with Imoen, Kagain, Eldoth and Branwen
Drasus party and Cloakwood Mines
Stinking Clouds (courtesy of Eldoth, carrying on Dynaheir's legacy...) and summons weren't enough to overcome Drasus' party. Very far from it, actually. Probably serves me right for being too cowardly to get within sight of the mages...
So we pulled back. For reasons I can't really explain now, Martha ran south and all the others ran north. This turned out to be both good and bad. Good because of two things:
- only Drasus followed Martha. So no risk for her to get disabled, she just had to make sure to keep her HPs up.
- Genthore (the axe thrower) lost track of both parts of my party.
Bad (of course) because it's hard to monitor and direct two simultaneous battles far apart.
A mages-only unit is (at least in BG1) clearly less dangerous than if there are fighters in there as well. The mages need to deliver all the damage themselves (or summon something that does) and most BG1 mages aren't very good at that. The fight was on. I mostly used ice arrows early on. They are useful because the cold damage can't be saved against, it can interrupt spells even on Stoneskinned mages while at the same time gnawing on said Stoneskins.

This was pretty scary, though. I realized that my quartet of characters WILL eat spells, and being Malisoned is not a good start. Branwen had cast Remove Fear and PfE 10' Radius but those buffs had been Remove Magic'd on all but Eldoth.
Meanwhile, Martha and Drasus had a private battle for quite a while. Drasus had two extra healers and after a LOT of fighting, she had him at Near Death for what felt like an eternity. Melee wasn't hopeless, they hit each other about equally well but it was too painful for Martha in the long run. I burned an Oil of Speed and tried to do run-and-hit with her boomerang dagger. Hit once but he was still standing. Finally decided to take my chances with a Call Lightning. Starting at maximum visible range, I figured that she would manage to finish the spell if Drasus would miss the one and only attack he'd have time for. Yup:

My quartet was in deep. Kagain Dominated, Eldoth Dire Charmed, Imoen very nearly killed by a Flame Arrow.
Both mages started to run out of spells now, but they still managed to charm Imoen:

She's a decent archer but could only see Branwen here, and Branwen is wearing Girdle of Piercing, Boots of Avoidance and a shield +1 here, plus she has S&S proficiency.
After the mages died, Imoen backstabbed Genthore while the rest of my party was just outside his view. He was at Near Death after the backstab. Imoen meleed him and the rest of us moved in and finished him off. Here is the brutal carnage in the initial fighting area. Those guys are no joke when you play with SCS.

Oh yeah, that tome was a reward they left.
We pillaged the barracks and the first Mines room, then went back to the map edge to rest. Did so succesfully. Now the plan was to do all of the Mines without more resting (because resting is pretty risky - the spawn packs of guards are large).
Second floor is nasty with SCS (the calls for help component) so Martha cast Pixie Dust and we all walked through it invisble. If you do not want to pass right by the mage (and risk her getting suspicious and dispel the invisiblity), there is one door that needs to be opened and doing so turns that character visible. I used Imoen to open that door. I suppose Branwen could have cast Sanctuary and done it, but that would have made me pressed for time to exit the place quickly before the Sanctuary times out. As it was now, Imoen managed to quickly dash through the door and hide in shadows, with the Ghast close by none the wiser. 
I made sure to have Imoen (in shadows) at the back of my party going down. If you do it like this, the stealth won't break. One advantage of not playing with a solo character.
Sneaky sneaky:

We moved to the last room, the one with a pair of Hobgoblin Elite. Then we moved alongside the left part, slaying Hobgoblins by the dozens. One good thing is that killing those SW of the starting room called out the three archers there, separating them from the human guards (haha, seems like human guards do not understand hobgoblin calls for help!).
Looted the place but left the two mages (Natasha and ogre mage) for later.
Went down to Davaeorn's floor. We took care of him the cheesy way - floor hopping as he recited spells. And like I've seen before, if D. stays upstairs, the Battle Horrors become inactive.
I experimented with Martha's boomerang dagger against them. They were immune to the damage if she threw the dagger but not if she stabbed them with it. Of course, some nifty loot here. Don't remember much of it, but there was at least a Tome of Understanding, giving Martha an extra level 1 spell slot .
Davaeorn had wandered a bit away from the stairs on floor 3. I gave Kagain a PfMagic scroll, and he proceeded to beat Davaeorn to death with his swords. Took a while, with all the Stoneskins, Mirror Images and such. He also defeated the other two mages with the protection intact. Branwen animated skeletons, so I could send in one at a time to coax the ogre mage out of invisibility the two times it got scared of Kagain and tried to camp him out.
Only the second floor left now, and plenty of good spells still available. Some more floor hopping separated Hareishan from the main bulk of guards. Decided to take them on here:

It wasn't so easy (we aren't combat monsters, apart from maybe Kagain) but we managed. Needed several healing potions, though. Hareishan was lured down here. She got off a Dire Charm on Kagain, before failing a save on her own, vs. Hold Person. Kagain had been clever to stuff his weapons in the backpack as the charm was flying towards him. Last thing I had to do was to keep telling my trigger happy friends to leave him alone:

I recruited Yeslick, both to save him and to have him help us carry all the loot.
Back at our base camp, I said goodbye to Branwen. Then I realized we were still in Chapter 4. Hmm, I've read all the letters, killed Davaeorn and flooded the mines. What's missing? Then it dawned on me that I had never been on the bottom floor after Davaeorn died. Using the console to move us there insta-solved the problem.
(BTW, my jaw would have dropped to the floor if that area actually had been full of water!)
Picked up Kivan at FAI so I could have the great exhange with Imanel Silversword.
Eldoth sure looks nifty in elven chainmail, don't you think?

There are many ways to miss out on or screw up quests. Here's one I had never thought of before:

On the very first (or maybe the second) stab it's ever used, it breaks - Nester's dagger!
Now why was Martha even using this? Well, after Imoen dual-classed, Imoen took over the Boomerang Dagger so she'd be at least somewhat useful in fights. This left Martha without a melee weapon, and her other weapon slot had only valuable Darts of Wounding. Far too valuable to use on the wimps we were fighting here. I tried to buy some plain darts for her but get this: none of the shops I visited in BG sold any plain darts! Plus it's often useful to have a melee weapon around anyway. Michael here was really getting on her nerves as he was annoying good at hitting Imoen (note that Imoen has moved away from his line of fire). Martha simply tried to protect her sister, and used the first cheap tool she could find!
I knew that Martha's old faithful Dagger +1 was back at the base camp but I thought "I'll just finish this fight, then go get it and buy plenty of darts."...
About Imoen's dual-classing: she reached Thief 9 from the reward we received for taking the Silvershield fibula to Skie's stepmother. I dual-classed her to Mage, changed that to Conjurer in SK, then used a method I found on a forum to give her the extra spell slots:
- download 'Imoen the Conjurer' mod and extract it somewhere outside the Override folder
- copy and rename one of the .cre files and drop it in the Override folder
- open the .cre file in SK using the Creature Browser
- open the savegame
- copy the parameters in the 'Affects' that deal with spell slots and give Imoen those 'Affects'.
I only bothered with the first five spell levels. She won't get to higher levels and there aren't any level 6 spell scrolls in BG1 anyway.
She has reached level 4 now and so far, it seems to be working as I want it to. The only thing I've found that isn't perfect is that when she opens up a new spell level (like when she reached level 3) the level up result said she had gained one level 2 spell slot when in fact it was two.
Clever sneaking in another phase spider infested area:

Spider is boxed in by invisble characters. Fish in a barrel for Kagain.
Eldoth drank a Master Thievery potion, took off his chainmail and pickpocketed the hell out of Arkion and Nemphre. In addition to their jewellery, he filched a Vampiric Touch scroll from Nemphre and Gauntlets of Ogre Power from Arkion. Kagain loves them. Ordulinian rewarded us with 3500 XP and a Cloak of Non-Detection. Now we have three of those.
Martha did go back to the base camp to get her dagger. We also got there to let Imoen scribe an obscene number of useful spell scrolls. What's up next is probably Garrick's quest in Ulcaster. I've read that the interaction between the two bards and Skie can get interesting. Before we recruited Skie, Eldoth was already sweet-talking up Imoen in a pretty-obviously-sleazy fashion. She didn't fall for it, though. Clever girl. And when Eldoth suggested to Skie that they go 'beyond a kiss', Imoen delivered a real stinger:

Martha, lvl 9 Totemic Druid, 67 HP
Imoen, lvl 9 Thief -> lvl 4 Conjurer, 35 HP, 2 deaths, CON=14
Kagain, lvl 7 Fighter, 72+5 HP, 1 death but CON still 20 thanks to tome
Eldoth, lvl 7 Bard, 32 HP
Skie, lvl 7 Thief, 29 HP